i'm sure the answer to this is really obvious but i just wanted to double check. good to be 100% sure!
If I sync my iPhone to my iTunes library to get my new songs....will it delete songs that aren't already in my library? I've purchased a lot of music but my boyfriend has download a lot of songs for me and used an external hard drive to put it on my phone. So if I sync to my own library now to get the new songs, will it delete the stuff that's on my phone - but not in my library??!

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